Improper Validation of Syntactic Correctness of Input in xmldom - CVE-2026-83611
Published: August 25, 2026 / Updated: September 2, 2026
Vulnerability identifier: #VU145130
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-83611
CWE-ID: CWE-1286
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass a well-formedness validation check.
The vulnerability exists due to improper validation of syntactic correctness of input in the xmldom parser when parsing XML end tags whose valid name is followed by a line break and trailing content. A remote attacker can supply specially crafted XML input to bypass a well-formedness validation check.
The trailing content is silently discarded, and the resulting DOM can appear as a normal single-root document instead of producing a parse error.
Affected software
xmldom
How to mitigate CVE-2026-83611
Install security update from vendor's website.
xmldom - addressed in versions 0.8.15, 0.9.12